The United Nations has warned that about 18 million people living in Africa’s Sahel region would face severe hunger in the next three months, citing the effects of Russia’s war in Ukraine, the coronavirus pandemic, climate-induced shocks and rising costs.

The dire situation could force more people to migrate out of the affected areas, according to the office for the Coordination of Humanitarian Affairs (OCHA) said on Friday.

The largest number of people are at risk of severe hunger across the region since 2014, and four countries — Burkina Faso, Chad, Mali and Niger — are facing “alarming levels”, with nearly 1.7 million people facing emergency levels of food shortages there, according to the UN agency.

Parts of the Sahel region, a vast territory stretching across the south of the Sahara Desert, have faced their worst agricultural production in more than a decade. Food shortages could worsen as the lean season arrives in late summer, Tomson Phiri, spokesman for the UN’s World Food Programme, said.

More reports have also shown that more people from the affected region outnumber other illegal migrants who seek to travel north to Europe in hopes of economic opportunity, more stability and safety.

“A combination of violence, insecurity, deep poverty and record-high food prices is exacerbating malnutrition and driving millions to the fringes of survival,” Martin Griffiths, the head of OCHA, said in a statement.

“The recent spike in food prices driven by the conflict between Russia and Ukraine is threatening to turn a food security crisis into a humanitarian disaster,” he said. Those two countries are key producers of wheat, barley and other agricultural products, and the conflict has almost entirely halted exports through the Black Sea.

Meanwhile, OCHA has said it would release $30 million from its emergency relief fund to provide the four affected countries with much-needed support.